By-pass valve for motor pumps



Feb. 9, 1932. MOGREGQR 1,844,668

BY-PASS VALVE FOR MOTOR PUMPS Filed Sept. 50. 1929 JQQQBTQL QKornug Patented Feb. a, less rarsur OFFICE GLA R EIIOE"E-. MOGREGOR, 0]? SPRING LAKE, MICHIGAN, ASSIGN'OR T0 BENNETT PUMPS COEEPQRATIGN; 0F IrE'USKEGGN, MICHIGAN, A CURPORATION OF MICHIGAN M BY-PASS VALVE FOR MOTOR PUMPS Application filed September so, 1929. Serial he. seems.

This invention relates to a safetyby-pass for motor operated pumps used iii-pumping liquids, and it is particularly useful in 0on5 unction with liquid dispensing pumps at gasolme service stations;

VJ 1th by-pass valves of the usual type, when the how of gasoline 1S stopped by closing the delivery nozzle positioned at the free end of the delivery hose used with pumps of this character, the continued operation of the pinup induces a pressure of liquid suiticient to open the valve and permit the liquid to circulate in a continuous passage from the pump through the valve opening and back to the pump. It has been found thatthe extent towhich the bypass valve will open is limited unless there is pressure induced to a degree much greaterthan is present in the ordinary operations of the pump, this being due to the progressively increasing force or resistance of the valve spring for the wider uncovering of the valve opening whereby, in order to take care of the valve operating requirements, the electric motor used for driving the pump must be of a considerably larger size than would be required merely for the pump oper- 0 1 ations for normal delivery or the gasoline and, of course, there is a very marlred increase in the amount of current consumed in ruin ning the motor when the gasoline is lay-pass ing past the valve.

WVith my invention a by-passvalve is produced wherein, during the normal pumping operations with the nozzle open for the pas sage of gasoline, the valve remains in securely closed position and will not open at all under such pressure as is produced by normal pumping operations. This valve, however,is so constructed and designed that it automaticallyopens to a fullopen position so as to freely by-pass the gasoline upon the attainmentof a pressure somewhat higher but not man hi ,her than the normal pressureof the liquid when itis being pumped for delivery through the hose. And it is the primary objectand purpose ofthe present inventionto provide a. simply constructed,

, durableand especially efiicient valve for the by-passing liquid to its purposes stated which is readily opened for fullest extent with high pressures.

out the necessity of trio power.

An understanding of the invention for the attainment of the ends stated, and of the construction which I have devised for embodying the invention, will be apparent from the following description taken in connection with the accompanying drawings, in which,

Fig. 1 is a fragmentary vertical section taken through a rotary pump between its front and rear sides and having my inventionof by-pass valve associated therewith, showing its place of use.

Fig. 2 is a central vertical section through the valvestructure, and

Fig. 3 shows in perspective and in disas sembled relation the several elements used in the construction of the valve.

Like reference characters refer to like parts in the difierent figures of the drawings.

The pump with which the by-pass valve of my invention is used includes a housing or casing 1, gasoline being drawn thereinto through an inlet pipe 2 into an inletchamber 3 at one side of the pump. The gasoline leaves the pump through an outlet pipe 4 from an outlet chamber 5 at the opposite side of the pump. A pump rotor chamber 6' of eccentric form is disposed between the chambers 3 and 5 in which the pump rotor 7 is mounted for rotation and which has a plurality of sliding vanes 8 therein. The rotor is eccentrically mounted with respect to the chamber 6 and the walls 9 of which have an outletopening 10 between the rotor chamber 6 and the outlet chamber 5 and an inlet opening 11 making communication between the inletchamber 3 and the rotor chamber 6. In operation. oi the pump its gasoline is drawn through the pipe 2 into chamber 3 and passes through the opening 11 into the rotor chamber 6 and is expelled therefrom through the opening 10 through the outlet chamber5 and thence through the outlet pipe 4, the direc cated by the arrow.

A by-pass 12 for the liquid extends around the under side of the rotor chamber 6 between its wall 9 and the outer housing 1 of the pump and communicates with a horizontal chamber 13 located below the outlet chamber and separated therefrom by a horizontal partition 14 which extends between the wall 9 and the outer side of the pump housing 1 as shown in Fig. 2. Below the partition 14: is a horizontal lower section 15 of the pump housing which forms the lower wall of chamber 13. The two partitions 14 and 15 have vertically aligned openings through which the by-pass valve of my invention passes.

The by-pass valve construction includes a cylindrical body 16 having an eXteriorly threaded lower portion and at its lower end isequipped with a suitable head 17 of ordinary conventional shape to receive a wrench for turning the body when it is threaded through the opening in the part 15 of the pump housing. This opening is interiorly threaded to correspond. with the threads e2:- teriorly provided at the lower part of the H body 16. Said body 16 is interiorly bored from its upper end downwardly providing two cylindrical openings, or chambers, a lower one 18 of a smaller interior diameter than the upper larger opening 19. These openings do not extend through head 17, which forms a closure at the lower end of the smaller diameter opening 18 as best shown in Fig. 2. A short distance below the upper end of the body 16 a plurality of slots 20 are, cut through the sides of the body 16 thereby making openings through the wall of the body which are separated by integral, vertical posts 21 as shown. That portion of the body above the upper end of the posts 21 preferably is of slightly reduced exterior diameter and is of a size to snugly fit the opening through the partition 1% previously described, entering thereinto when the body of the bypass valve is threaded into place thereby bringing the slots 20 below the lower side of the partition.

A ball 22 is located in the bottom of opening or chamber 18 serving to automatically center itself in the conical lower end of said chamber. A coiled compression spring 23 at its lower end bears against the ball and extends upwardly into a valve member slidably received with the body 16. This valve member is of cylindrical form having an upper portion 24 of an exterior diameter such that it fits readily within the larger chamber 19, and having a depending smaller cylindrical portion 25, the exterior diameter of which is such that it is readily entered into the up per portion of thelower chamber 18.. The valve member is interiorly bored from its lower end upwardly nearly through the upper larger portion. 24: providing a cylindrical opening 26, the diameter of which is. such that the upper part of the coiled spring 23 is freely received therein. An opening 27 of small size, is made through the upper end of the sliding valve member as shown. In the side of and near the upper end of the enlarged part 24tof the valve member a narrow horizontal slot is out which does not extend through to the interior opening 26, and a small vertical passage 29 is made upwardly from the shoulder between the sections 2 1 and of the valve member until it commu nicates with the slot 28.

The passage 29 should be of such size as to permit free communication between the slot 20 and the chamber 19 to relieve the pressure in the latter incident to outward dis placement of the valve 2 1.

The parts are assembled by dropping the ball 22 into the chamber 18, placing the lower end of the spring 23 against the ball, placing the valve member over the upper end portion of the spring and inserting the same into the body 16 and compressing the spring so as to move the valve member to a desired lower position whereby a cross pin 30 may be inserted through openings in the opposite sides and near the upper end of the body 16 so the pin lies across the upper end of the valve member. This holds the parts in assembled relation and when the valve construction is applied to the pump housing 1 as shown in Fig. 1, by threading the same through the opening in the side 15, the cross pin is held against any outward movement as its ends are stopped by the sides of the opening in the partition 1 1 as shown.

During normal pumping operations some of the gasoline which is pumped into the out let chamber 5 will pass through the opening 27 and fill the various chambers 18 and 19. The fit of the parts is fairly close so there is but little leakage around them and there is thus in addition to the pressure of the spring 26 which normally holds the valve in closed position, a back pressure from gasoline within the body of the valve structure helping to maintain the valve closed.

In the normal operation of the pump there is some pressure of liquid against the upper end of the valve and tiere is substantially the same pressure or a back pressure against the lower end of the part 25; but due to the vacuum created in the by-pass 12 there is practically no back pressure in the chamber 19 against the shoulder between the two parts 24 and 25 of the valve as the vacuum in the by-pass 12 tends to relieve any pressure in the chamber 19, there being a tendency to draw the liquid in the chamber 19 around the upper larger portion 24 of the valve to the slots or ports 20. The area of, the upper end of the valve part 24:, being larger than the area of the lower end of the part 25, the effective pressure tending to compress the spring 23 is a multiple of the pressure in pounds per square inch of the difference in 'area between the larger part "24 and the smaller part 25 of thevalve. The spring accordingly has to be of sufiicient strength only to withstand and overcome this .efi'e tive pressure so that thelupper end of the I valve part 24 will not be depressed to a point to open the relief slot 28 and bring it into conjunction with the ports 20 during a normal pumping operation. r

. When the flow of liquid at the delivery 1102-. zle is cut oil and the motor continues to run, the pressure is increasedin the chamber .5 sufiicient to overcome the spring and move the valve in a downward direction and bring therelief slot28 into conjunctionwith the portsQO; .As soon as this occurs thereris a quick relief of any pressure in the chamber 19 caused by forcing the valve downwardly faster than the liquid can; escape around the valve, and the valve thereupon moves downwardly quickly and opens the ports 20 s lt-- ficiently to carry the normal flow of liquid thatis being pumped. a

- sary opening of the ports 20 to the by-pass to take the entire flow otliquid that the pump will pump. By reason- 01 only apart ofthe cross sectional area of thelarger part 24 0f the valve being eilective with relation to i the pressure of liquid on the valve, 1t 1s not.

necessary to have the much stiller spring which wouldibe required 1f the totalarea. ot the upper end otthe valve part Qtwasellectire. under the pressureot the liquid; and this permtits the proper by-pass of the liquid Without the need ofusing a heavier and more expensive motor, to overcome a much heavier pressure which would have to be pro duced toopen a valve having the still spring.

In practice this valvemay be used with motor operated pumps either with oneor two delivery hose outlets thereto. An example w'ill illustrate the use ot the-valve of my invention: 2

In one of: the pumps with which in vention isparticularly useful, asingle pump unit has'associated therewith two meters and two outlet nozzles both fed from the same pump unit When both nozzles are open the 1 rate of pumping is eleven and one-half gallons per minute, and the valve is substantially at its upper position shown in Fig. 2, at

least, it is but slightly below the rod 30 and maintains this position and keeps theports 720 closed. When one nozzle is shut off, the

.This valve movement provides the neces.

to bypass 8 gallons per minute. Onshutting off both nozzles. with themotorcontinuing in operation, the pressure is 11 pounds per squareinch and the entire 23 gallonsper minute I which the pump pumps passes throughthe ports 20-, the valve, being opened to its full extent.

The construction describedis one, which ly has to "resist such eitective pressure. .The

relief of pressure in the chamber 19 occurs as soon as'the slot 28.,comes into conjunction with any port 20 permitting a quick action of the valve under the higher pressures p'ro ducedswhen the flow of gasoline is Wholly or partly cutoff. Without this relief-thus provided by. the slot 28 and the passage 29, a' downward movement of the valve would be sluggish and cause aconsiderable overload, on the motor until gasoline had been forced out of the chamber 19 to the portsQO through thesmall space'between the sides of the charm ber 19 and the larger part 5240f; the valve,'

and would require that the, motor be otsuf ficient capacityto takecare of this overload for theshort time that it would exist; while with the useof therelief passage and'slot described overloading, or stopping andburm ing out ofthe motor is obviatedeventhough the motor is of considerably less size and capacity than has previously been used.

The pressure of liquid in the chamber 5 necessaryto move the valveto'proper posi-; tion to pass all or'part of the liquidpumpedi pump is much less than in spring by the controlled valves. This permits, accordingly, use of a motor or a smaller capacity,as the motor does'not have to be of a capacity to take care ofheavy overload conditions pre viously met with because of the typeof by- I pass valve used. In addition there is a great; (lGCI'Bfl'SGflIl.COllSLHIlPtlOIl of current, during the timethatthe"motor is run alter theclosing of anozzle ornozzles. i Slot 28 is of considerable lengthfsowas to be greater than the width of anypost 21 thereby precluding any.

covering of the'slot by a post which would render the construction inefl'ective to per-1 form its designed operation. As an alternative the slot may berepla'ced by a continuous groovecut around the valve at the same plane asfslot 28. i I

. The suction fromthe intakeside ofthe pump through the ports 20 does not havethe effect ofrelieving pressure. within the cham-- ber 19. Other types of valves previously" used requirea springpressure adjustment to set the valvefor dififerent depths oftanks and varying degrees of vacuum encountered in raising the gasoline when it is pumped. This valve operates substantially the same irrespective of the depth from which the liquid must be raised, can be designed for any given by-pass pressure and can not be set to a dangerous pressure through ignorance. This invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1. A valve of the class described comprising, a valve body having a chamber extending longitudinally from one end thereof toward the opposite end and an opening through its side, said longitudinal chamber in the valve body being of greater cross sectional area at its outer end portion than at its inner end portion, a movable valve mounted within said body having its outer end portion of a cross sectional area substantially equal to the cross sectional area of the larger portion of said longitudinal chamber in the valve and its inner end portion of substantially the same cross sectional area as the smaller inner portion of said longitudinal chamber in the body, said valve having a longitudinal opening therein from its inner end nearly to its outer end and a small opening through its outer end, a spring located in the opening of said valve member and hearing against the bottom of the opening in said body tending to move the valve member outward and means limiting the extent of outward movement of said valve member, said valve member having a relief passage in the larger portion thereof extending from the inner end thereof nearly to its outer end and thence laterally to a side thereof, the upper end of the relief passage normally being located upward from the side opening in said body.

2. In a valve construction, an elongated body having a longitudinal passage, said passage extending from the inner end of the body partly through the same, a valve slidably mounted within said body, spring means tending to move the valve outward, means for stopping the outward movement of the valve, said valve having a restricted opening therethrough for the passa geof liquid whereby pressure of liquid against the outer end of the valve is partially counterbalanced by liquid passing through the valve into said body, said body having an opening inits side a distance from the outer end of the valve,

and means for relieving the counterbalancing pressure on the valve when the valve has been forced inwardly by pressure on the outer end thereof a predetermined distance, thereby permitting the valve to move quickly'inward a distance suificient to uncover said opening in the side of the body.

3,. A valve construction of the class described, comprising, a cylindrical body having a passage from its outer end inwardly longitudinally for a-distance and then a passage of smaller diameter nearly to the end of said body, a head at the other end of said body closing said opening, said body having a passage in a side thereof a distance from the outer end of the body, a valve member slidably mounted within the body comprising an outer cylindrical portion to fit the larger part of said longitudinal passage and an inner cylindrical portion extending into the smaller part of said longitudinal passage of the body, said valve member having a relatively large longitudinal opening from its inner end nearly to its outer end and a restricted opening through said outer end, a coiled spring located within the larger opening in said valve member and hearing at one end against said head, said larger portion of the valve member having a passage extending lengthwise thereof from a shoulder at its inner end between it and the smaller portion of the valve member to a short distance from the outer end of the valve member and having a narrow slot cut in the side of the larger portion of the valve member to communicate with said last described passage, the slot in the normal position of the valve member being located between the outer end of said bpdy and the passage through the side there- 0 4. A valve construction comprising, a valve housing having a longitudinal passage leading thereinto, said passage being of two different diameters and closed at its bottom, said smaller passage terminating at the bottom, a valve comprising two diiferent sized cross sections adapted to slidably and snugly engage the passage, means for limiting the reciprocation of the valve, said valve having a longitudinal passage therethrough whereby liquid pressure on its larger outer end is transmitted to its smaller inner end, said valve housing also having ports adapted to be uncovered by the inward movement of the valve.

In testimony whereof I afliX my signature.

CLARENCE E. MoGREGOR. 

